Engine dies at slow speed

Hey Le Frog,

Where do you have the ignition selector set at? HI or LO.

I had a similiar problem with my 01 501 in that when I would run the selector in HI, everything would be fine for a while, then all of a sudden, at slow speed, just when I would start to open the throttle it would start to bog a bit, I'd gas it and it would recover. As time progressed, the same situation would occur but, the bike would just keep on bogging and die. No amount of changing the selector back to LO and HI would matter. I found that if I just left it in LO I didn't have any problems, until one day during a race it did the same thing in LO, at low speed start to open the throttle and bog and then die. Almost like it was running out of gas. Well, after having my motor down for a long time, and when I finally got it running again, I was out breaking the motor in and it did the same thing except this time it would not re start with the kicker or the e start, both of which always started my bike before.

My solution was to replace the top coil as I had a similar problem when the bike was new. Except that then it was like someone would just reach up and push the kill switch for a moment. This was a known problem on the 01's, so if it's the original it's very likely that could be the culprit.

On the new top coil the grey wire has been eliminated, thus, no more HI LO adjustment. It's just always going to be in the HI mode I'm assuming. Since replacing my top coil I haven't had any more problems. Be sure and check all your other wiring to make sure you don't have a short in the orange wire which is the ignition grounding wire. You might want to even take the stock kill switch assembly apart to make sure it isn't full of dirt, and to make sure the contacts aren't too close together. Also check around the key switch area as the orange wire is vulnerable there as well. Check all this stuff first, but, by the sounds of it my bet is it's going to be that top coil.

Have you checked the air screw setting? It might be set just a little to low. I had a problem a while back and turning the screw out 1/8 to 1/2 out took care of it. That is more than likely caused by a very simple thing. This is not the idle screw but the other one. Glad you are riding some, the more you ride the better you will get and also the more used to the bike you will get. Hope this helps.

did you ever check your ignition timing?

it's amazing how many people, having heard mine was out have never ever checked their proper timing. i read my report the other day;

"advanced the igniton twice and each time the tickover went up as well (always a good sign BTW!).

regards

Taffy

Could it be that the SEM ignition does not work below 700 rpm? Just asking?

Let me know what you come up with. I just recently bought my 01 470 and it sounds like it's the same way. My Ktm 200 seams a lot smoother in the tight stuff. A friend of mine has a auto clutch on his 470 and seam to make the difference between stalling at low rpm's because it never runs lower thanabout 1200 rpm.

When looking at the carb, pay attention to the choke mechanism. If it hangs up a little bit, you could have this effect when you roll off the throttle at low rpm.
Good Luck